Air conditioning apparatus



Oct. 13, 1964 A. H. EBERHART 3,152,454

AIR CONDITIONING APPARATUS Filed Dec. 18, 1963 2 Sheets-Sheet 1 Fig. I.

Fig.2

wnmzssss: INVENTOR 891M032 (QC; Arthur H. Eberhort 2 Sheets-Sheet 2 Filed Dec. 18, 1963 117111111, IIIIIIIIIIIIIIIIIIIIIII 1111111 111/ 1111 IIII Fig. 3.

United States Patent 3,152,454 ARR CGNDITIONING APPARATUS Arthur H. Eberhart, Hiiliard, Ghio, assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Dec. 18, 1963, Ser. No. 331,475 7 Claims. (U. 6215tl) This invention relates to air conditioning apparatus and more particularly to condensate disposal arrangements for self-contained room air conditioners.

In a self-contained room air conditioning unit wherein a refrigerating system is employed to cool the air of an enclosure, a great amount of moisture condenses on the cool heat exchanger and drains from the heat exchanger surfaces as condensate water. Heretofore, it has been found that the condensate water, when deposited on the condenser or warm heat exchanger, increases the efficiency of the unit by lowering the discharge pressure of the heat exchanger thereby increasing the heat absorbing capacity of the liquid refrigerant circulated to the evaporator. It is, therefore, common practice to dispose of condensate removed from the room air by depositing it onto the outside heat exchanger, or condenser where it is evaporated into the outside air.

Slinger rings, and other water lifting devices, operating in conjunction with the condenser fan and a condensate sump, are generally employed to lift the condensate into the condenser air stream.

With the advent of air conditioning units which provide for both heating and cooling an enclosure, it is becoming a more common practice to operate air conditioning units on a year round basis. The operation of an air conditioning unit wherein the condensate is deposited on the condenser provides a number of problems when the outside ambient approaches the freezing temperature of water.

When the outside ambient is at, or below, the freezing temperature of water the blades of the condenser fan may freeze in the condensate in units employing slinger rings or other such devices. In reverse cycle refrigerating systems, a further problem exists when the outside heat ex changer operates as a refrigerant evaporator during the heating cycle. During reverse cycle operation the condensate to be disposed of forms on the cold outside heat exchanger and it is therefore quite obvious that it must be disposed of by draining it from the receptacle. The heat exchanger may be operating at a temperature lower than the freezing point of water when the outside ambient is well above that temperature. In this situation, the discharge of condensate on the cold heat exchanger surface tends to form ice, which prevents proper air flow through the heat exchanger and lessens the efliciency of the unit. It is obvious that when either of the above conditions are present, the condensate water should be removed from the unit by means other than by discharge on the outside heat exchanger surface.

In addition, it has been found that units employed for heating or cooling enclosures are often operated on the cooling cycle when the outside ambient is in the 40 to 50 F. range. This condition is often caused by a large number of persons gathered in a small enclosure, inadvertent overheating of the enclosure, a sharp rise in temperature due to cooking at meal times, etc. Under such conditions, it has been found that the use of condensate water and resultant decrease in discharge pressure from the condenser, causes the evaporator, or inside heat exchanger, to frost up and thereby decrease its efiiciency. It is, therefore, obvious that under this condition, also, the discharge of condensate water on the outside heat exchanger is highly undesirable.

The present invention provides a means for controlling the draining of condensate water from the unit, and has an object to remove the water from the unit at all times when it is undesirable to utilize such water for condenser cooling purposes.

Another object of the invention is to provide air condtioning apparatus which makes optimum use of condensate Water.

A further object of the invention is to provide an automatic condensate drain for an air conditioning unit, which is simple to manufacture and incorporate in the unit, yet is extremely effective in maintaining the efiiciency of the refrigerating system during all cycles of operation.

These objects of the invention, and other objects which will become apparent as the description proceeds, are achieved by providing an air conditioning unit having a receptacle for collecting condensate water and a suitable means for depositing the condensate on the surface of the outside heat exchanger. A means for draining the con densate water from the receptacle includes an opening disposed at a low point in the receptacle, and a closure memher for the opening which member is operated by a plunger arrangement in response to a novel temperature sensing means.

The novel temperature sensing means comprises a bellows operatively connected to the plunger, and a sensing capillary tube connected to the bellows. The bellows and capillary tube arrangement are of a type well known in the art and generally referred to as the limited vapor fill type. The gas filled, or limited vapor fill control operates on the principle of a phase change from gas to liquid, or vice versa depending on the temperature of the air surrounding the control. In such an arrangement, the control point can be either along the capillary or the bellows and the control responds to whichever point is colder.

In the present invention, the plunger and bellows assembly is disposed in the outside air flow upstream of the condenser, or outside heat exchanger, and the capillary tube is disposed such that a portion is located in the outside air flow downstream of the heat exchanger. Thus, by providing a vapor filled bellows-capillary tube structure, which is actuated when the temperature falls below a predetermined temperature, the condensate drains from the unit in response to a cold temperature sensed at a point either upstream of the outside heat exchanger, or downstream of the heat exchanger, thereby achieving the desired objective.

For a better understanding of the invention, reference should be had to the accompanying drawings, wherein:

FIGURE 1 is a top plan view showing a room air conditioner unit in which the invention is employed, having portions of the structure broken away to better show the invention;

FIG. 2 is an elevational view, partially in section, taken along line IIII of FIG. 1, showing details of the invention; and

FIG. 3 is a transverse sectional view taken along line III-III of FIG. 1, showing details of the structure.

Although the principles of the invention are broadly applicable to self-contained air conditioning units, the invention has been herein illustrated as employed in a unit for heating or cooling the interior of an enclosure and having a refrigerating system operable as a reverse cycle system.

Referring to the drawings, especially FIGS. 1 and 3, there is shown a self-contained room air conditioning unit 10 having a housing 11 in which is contained a refrigerating system of the reverse cycle type. The refrigerating system comprises a compressor 12 having an inlet tube 13 for gaseous refrigerant and an outlet tube 14 for high pressure gaseous refrigerant, both connected to a reversing valve 16 which may be of any type well known in the art. An outside heat exchanger 17 is disposed adjacent a side of the housing 11 which is to be exposed to a the outside ambient. At the opposite side of the enclosure 11 there is located an inside heat exchanger 18 of the finned tube type, and a blower 1 .9 driven by an electric motor 21 for causing air to flow from the enclosure and over the inside heat exchanger. The heat exchangers 1'7 and 18 are connected in series flow by a capillary restrictor tube 22 or through a suitable expansion valve or other pressure reducing device or devices, the inlet or outlet of which is shown on the inside heat exchanger and the outlet or inlet of which is shown on the outside heat exchanger. The refrigerant flow path through the inside heat exchanger 18 is connected to the reversing valve 16 by tube 23 and a tube 24 provides communication between the reversing valve and the outside heat exchanger 17.

A detailed description of the various components of a reverse cycle refrigerating system as shown has not been presented, as such systems are well known in the art, and such details form no part of the present invention. It is sufficient to say that during the heating cycle the thermostat sensing a predetermined lower temperature of the enclosure causes the reversing valve to produce flow of hot gaseous refrigerant as shown by the dotted arrows in FIGS. 1 and 3. Gaseous refrigerant flow through the tube 23 and into the heat exchanger 18, which serves as a condenser, thence through the restrictor tube 22 or other pressure reducing means to the outside heat exchanger 17 which serves as an evaporator. The cold gaseous refrigerant then flows from the outside heat exchanger 17 through the tube 24 and back to the compressor 12. When the enclosure thermostat calls for cooling, the reversing valve 16 is actuated to cause fiow of hot gaseous refrigerant through the tube 24 and through the system previously described in a reverse manner, as shown by the solid arrows of FIGS. 1 and 3.

As best shown in FIG. 1, the electric motor 21 is connected to a bladed impeller 26 disposed adjacent an opening in a shroud 27, for causing outside air to flow through the housing 11, as shown by the arrows. The shroud 27 is provided with an aspirator 255 for lifting water collected in the housing 11 from directly below the aspirator and into the air flow, where it is deposited on the surface of the heat exchanger 17.

The shroud and aspirator arrangement shown is more fully described in the copending application of Arthur H. Eberhart and Michael D. Ulich, Serial No. 261,258, filed Februray 27, 1963 and assigned to the assignee of the present invention. However, it should be understood that the present invention is not limited to the means shown for lifting the water into the outside air flow, as numerous arrangements such as slinger rings, syphon arrangements, etc. are well known to those familiar with the art.

Referring to FIG. 3, it will be noted that the inside heat exchanger 18 is mounted above a drain pan 29 provided with a drain tube 31 extending into the outside portion of the housing 11. In the structure shown, the unit It) is adapted to be mounted in a wall opening or window in such manner that the lower wall of the housing 11 is slightly tilted causing water to flow to the outside air section adjacent the aspirator 28. The unit may also be constructed with the pan member 29 slightly tilted from the horizontal and the lower wall of the housing 11 slightly tilted, or in any other manner which will provide a condensate water collecting means adjacent the outside wall of the housing and below the aspirator 28.

In FIGS. 1 and 2, it will be observed that the portion of the housing 11 provided for collecting the condensate water is provided with an opening 32 having a conical shaped rubber plunger 33 serving as a closure member therefor. The plunger 33 is disposed on the end of a shaft 34, which is operatively connected to a bellows 35 supported in a metal casing 33. The casing 38 is riveted to a Z-shaped member 40 which is bolted to the housing 11 and serves to support the upper end of the bellows 36 in fixed spaced relation to the opening 32. A capillary tube 39 is connected to the top opening in the bellows 36 and extends adjacent the outside face of the heat exchanger 17 where it is supported at an edge of an upturned flange 41 of the housing 11 by a pair of clips 42 and 43. The tube 39 and the bellows 36 comprise a vapor filled type temperature sensing element as previously described which operates the bellows 36 by a change in the fluid from a gas to a liquid or vice versa.

In practicing the present invention, it has been found that good results are achieved by providing a temperature sensing element (bellows 35 and tube 39) which operates to maintain the plunger 33 in a closed position in the opening 32 when a temperature of above 67 F. is sensed at all points thereon, and which completely removes the plunger from the opening 32 at a temperature of 47 F. or lower.

In operation, during all heating cycles when the control tube 39 is sensing the cold temperature of the air leaving heat exchanger 17, or the bellows 36 is sensing the cold ambient, the drain remains open. During the cooling cycle, with a normal warm outside ambient, both the bellows 35, sensing the warm ambient and the tube 39, sensing the warm temperature of the heat exchanger 17 operating as a condenser, will be above a temperature of 67 F. and the opening 32 will be closed, providing condensate water for use as condenser coolant.

However, during a cooling cycle, when the outside ambient is in the area of say 45 to 55 F., the tube 39 is at a high temperature due to the heat from the heat exchanger 17, but the bellows 36, sensing the low ambient, causes the plunger 33 to open the drain 32 and thereby dispose of the condensate water.

From the foregoing, it should be evident that the various objects of the invention are achieved by the provision of a novel arrangement for the disposal of condensate water, which arrangement is simple in construction and may be easily adapted for air conditioning units presently in use.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

What is claimed is:

1. Apparatus for conditioning the air of an enclosure, comprising:

a housing;

a refrigerating system in said housing having a first heat exchanger,

air translating means for causing air to flow from said enclosure and over said first heat exchanger,

a second heat exchanger, and

air translating means for causing outside air to flow over said second heat exchanger;

means for collecting water condensed on one of said heat exchangers,

said water-collecting means having means for draining the condensate water therefrom; and

a temperature sensing element operatively connected to said drain means and having a portion thereof disposed in said outside air flow upstream of said second heat exchanger,

and a portion thereof disposed downstream of said second heat exchanger,

said temperature sensing element functioning to cause said drain means to open and thereby drain water from said water-collecting means when one of said sensing element portions falls below a predetermined temperature.

2. The structure as in claim 1, further characterized by said predetermined temperature being in the range of from 45 F. to 70 F.

3. Apparatus for conditioning the air of an enclosure, comprising:

a. housing;

a refrigerating system in said housing having a first heat exchanger,

air translating means for causing air to flow from said enclosure and over said first heat exchanger,

a second heat exchanger, and

air translating means for causing outside air to flow over said second heat exchanger;

means for collecting water condensed on one of said heat exchangers,

said water-collecting means having means for draining the condensate water therefrom;

means in said housing for lifting water from said watercollecting means and into said outside air flow upstream of said second heat exchanger, to deposit water on said heat exchanger; and

a temperature sensing element operatively connected to said drain means and having a portion thereof disposed in said outside air flow upstream of said second heat exchanger and a portion thereof disposed downstream of said second heat exchanger,

said temperature sensing element functioning to cause said drain means to open and thereby drain water from said water-collecting means when one of said sensing element portions falls below a predetermined temperature.

4. Air conditioning apparatus operable for heating or cooling the air of an enclosure and comprising:

a housing;

a reverse cycle refrigerating system located in said housing and including an inside heat exchanger operating as a refrigerant evaporator during the cooling cycle, and as a refrigerant condenser during the heating cycle of said system,

an outside heat exchanger operating as a refrigerant condenser during the cooling cycle and as a refrigerant evaporator during the heating cycle of said system, and

air translating means for causing air from outside said enclosure to flow over said outside heat exchanger;

a receptacle for collecting water condensed on one of said heat exchangers,

said receptacle having means for draining the condensate water therefrom; and

a temperature sensing element operatively connected to said drain means and having a portion thereof disposed in said outside air flow upstream of said outside heat exchanger,

and a portion thereof disposed downstream of said outside heat exchanger,

said temperature sensing element functioning to cause said drain means to open and thereby drain water from said receptacle when one of said sensing element portions falls below a predetermined temperature.

5. The structure as in claim 4, further characterized by said predetermined temperature being in the range of from 45 F. to 70 F.

6. Air conditioning apparatus operable for heating or cooling the air of an enclosure and comprising:

a housing;

a reverse cycle refrigerating system located in said housing and including an inside heat exchanger operating as a refrigerant evaporator during the cooling cycle and as a refrigerant condenser during the heating cycle of said system,

an outside heat exchanger operating as a refrigerant condenser during the cooling cycle and as a refrigerant evaporator during the heating cycle of said system, and

air translating means for causing air from outside said enclosure to flow over said outside heat exchanger;

a receptacle for collecting water condensed on one of said heat exchangers,

said receptacle having means for draining the condensate water therefrom;

means in said housing for lifting water from said receptacle and into said outside air flow upstream of said outside heat exchanger; and

a temperature sensing element operatively connected to said drain means and having a portion thereof disposed in said outside air flow upstream of said outside heat exchanger,

a portion thereof disposed downstream of said outside heat exchanger,

said temperature sensing element functioning to cause said drain means to open and thereby drain water from said receptacle when one of said sensing element portions falls below a predetermined temperature.

7. The structure as set forth in claim 6 wherein said temperature sensing element comprises an elongated tube integrally connected to a movable bellows,

References Cited in the file of this patent UNITED STATES PATENTS Slattery Jan. 15, 1957 Smith Sept. 3, 1957 McMillan Nov. 10, 1959 McMillan Nov. 29, 1960 

1. APPARATUS FOR CONDITIONING THE AIR OF AN ENCLOSURE, COMPRISING: A HOUSING; A REFRIGERATING SYSTEM IN SAID HOUSING HAVING A FIRST HEAT EXCHANGER, AIR TRANSLATING MEANS FOR CAUSING AIR TO FLOW FROM SAID ENCLOSURE AND OVER SAID FIRST HEAT EXCHANGER, A SECOND HEAT EXCHANGER, AND AIR TRANSLATING MEANS FOR CAUSING OUTSIDE AIR TO FLOW OVER SAID SECOND HEAT EXCHANGER; MEANS FOR COLLECTING WATER CONDENSED ON ONE OF SAID HEAT EXCHANGERS, SAID WATER-COLLECTING MEANS HAVING MEANS FOR DRAINING THE CONDENSATE WATER THEREFROM; AND A TEMPERATURE SENSING ELEMENT OPERATIVELY CONNECTED TO SAID DRAIN MEANS AND HAVING A PORTION THEREOF DISPOSED IN SAID OUTSIDE AIR FLOW UPSTREAM OF SAID SECOND HEAT EXCHANGER, AND A PORTION THEREOF DISPOSED DOWNSTREAM OF SAID SECOND HEAT EXCHANGER, SAID TEMPERATURE SENSING ELEMENT FUNCTIONING TO CAUSE SAID DRAIN MEANS TO OPEN AND THEREBY DRAIN WATER FROM SAID WATER-COLLECTING MEANS WHEN ONE OF SAID SENSING ELEMENT PORTIONS FALLS BELOW A PREDETERMINED TEMPERATURE. 